311 
Bibliographical Notices. 
perhaps from the commencement and its full development thereby 
having been unimpeded, and states that the Proteus feeds upon 
its like as well as upon other matter, inclosing its food within its 
own substance after the manner of the Hydra. 
While examining the transparent border of a portion of sponge 
growing from the seed-like bodies, he has observed the contract- 
ing vesicles distinctly, and a little within this, the animals them- 
selves distinguishable, though amassed together and ever chan- 
ging their form ; but he does not appear to have ever seen them 
inclose an object within their substance after the manner of the 
Proteus. 
In the development of the contents of the sporangia or seed- 
like bodies, he observes, that when the latter are opened under 
water in a watch-glass, the transparent cells within them, having 
been eliminated, swell and are bursted by the imbibition {endos- 
mose) of that fluid ; and that then the true ova of the Sponge with 
which they are filled, spread themselves over the surface of the 
vessel. Each ovum appears, not to be globular or ovoid as he 
formerly supposed, but discoidal, very much resembling in size 
and appearance the globules of the blood, it being only when 
they are turned on their edges that they appear ovoid. The red 
spot in their centre he also now thinks to be an optical illusion, 
while he has every reason to believe that the ovum retains its 
planiform state until its transparent vesicles and granules have 
become developed and the power of locomotion in it fully esta- 
blished. — Ed. 
BIBLIOGRAPHICAL NOTICES. 
Rare and Remarkable Animals of Scotland, represented from living 
Subjects ; with practical Observations on their Nature. By Sir 
John Graham Dalyell, Bart. Volume first, containing fifty- 
three coloured Plates. London : John Van Voorst, Paternoster 
Row, 1847. 4to. Pp. 270. 
[Continued from p. 139.] 
The most interesting chapter in this interesting volume is that 
which narrates the history of the Hydra tuba. This marine animal 
is called a Hydra by our author because it has the form and the cha- 
racters of the freshwater polypes, and possesses also their qualities — 
their greed of living prey (p. 87), their proliferous evolution of 
5mung, their endurance of privations, their power to recover from 
apparently immedicable wounds, and their strange germinations and 
monstrosities under the influence and direction of the experimen- 
talist (p. 93). This hydra is found attached to submarine bodies ; 
the body is fleshy, inversely conical, encircled on the oral disc with 
